A method for changing the hereditary characteristics of pea plants. Purpose of the work: to prove that fitness is a general property of organisms. Non-hereditary traits of peas.

Variability- the ability of living organisms to acquire new characteristics and properties. Variability reflects the relationship of the organism with the external environment.

Distinguish non-hereditary And hereditary variability.

Non-hereditary variability

Non-hereditary variability is associated with changes in phenotype. Phenotypic changes caused by known environmental factors are called modifications. The limit of modification variability determined by the genotype is called the reaction norm. There are no changes in the genotype itself. The modifications are not transmitted to the next generation and disappear after the effect of the factor causing them has ceased.

Environmental factors (light, temperature, humidity) affect the functions of genes and the development of the organism. For example, primrose has red flowers in room conditions at a temperature of 18-20 o C. If you increase the humidity and raise the temperature to 30-35 o C, then the action of the genes responsible for color is suppressed, and the flowers will be white. If the plant is returned to its previous conditions (18-20 o C), then the primrose will have red flowers. Seeds collected from plants with red and white flowers will produce offspring depending on environmental conditions. It is not the trait (flower color) that is inherited, but the type of biochemical reaction to environmental conditions. The occurrence of modifications is associated with the influence of environmental conditions on enzymatic reactions occurring in the body.

Modification variability signs such as height, weight, color, etc. are affected. Some signs of an organism vary widely. These are quantitative characteristics (body weight, flower color). Others have a narrow reaction norm. These are qualitative signs (eye color, blood type in a person).

Modification variability corresponds to the living conditions of organisms and is adaptive.

Hereditary variability

At hereditary variability occurs changes in the characteristics of the organism, which are determined by the genotype and persist over a number of generations. Genotypic variability may be combinative And mutational.

Combinative variability

Combinativevariability is associated with the acquisition of new combinations of genes in the genotype, which leads to the emergence of organisms with a new phenotype. This occurs as a result of independent chromosome segregation during meiosis; their random combination during fertilization; gene recombination as a result of crossing over; gene interactions. The genes themselves do not change.

Combinative variability in humans can explain the appearance of blood groups II and III in children, in contrast to groups I and IV in their parents. The difference between children and parents is explained by the combination of the genes of their parents in the genotype of children.

Associated with combinative variability is the phenomenon of heterosis (increased hybrid vigor), which is observed in the first generation during hybridization between different plant varieties. Hybrids increase growth, viability, and productivity.

Breeders use hybridization to develop new breeds of animals or plant varieties.

Heterosiscan be explained by the fact that in hybrids the number of dominant genes that influence the development of the trait increases. For example, it can be assumed that genes A and B influence growth. As a result of crossing individuals with genotypes AAbb and aaBB,

A hybrid with the AaB genotype of higher growth is obtained. This is explained by the complementary action of the gene.

Sometimes a heterozygous organism has more pronounced characteristics than dominant homozygotes.

Mutational variability

Mutations- sudden hereditary changes in genetic material that occur for no apparent reason (spontaneously), or can be induced by external influences on the body. The process of mutation occurrence is called mutagenesis. Factors that cause mutations are called mutagens.

Mutations happen dominant(manifest in the first generation) and recessive, useful and harmful. If a harmful mutation is dominant, the organism may not be viable. Mutations that reduce viability are called semi-lethal, for example the appearance of the recessive hemophilia gene in humans. Mutations that are incompatible with life are called lethal.

Mutations happen generative(occur in germ cells and appear in the next generation) and somatic(manifest in a given organism, are not inherited during sexual reproduction and are transmitted during asexual reproduction).

According to the level of occurrence, mutations can be associated with changes in:

. gene structures - gene;

. chromosome structures - chromosomal rearrangements;

. chromosome numbers (polyploidy, heteroploidy) - genomic.

Gene (point) mutations occur when the chemical structure of a gene changes. There is a violation of the nucleotide sequence in the DNA molecule. This leads to a change in the structure of the protein. Gene mutations occur during replacement, loss

denia, insertion of nucleotide pairs. Most mutations are genetic (for example, yellow and green pea seeds).

Chromosomal rearrangements occur as a result of chromosome breakage. There are intrachromosomal rearrangements - deletions, duplications, inversions - and interchromosomal rearrangements - translocations.

Deletion(deficiency) - loss of part of a chromosome

DE plot shortage:

Duplication(doubling of a chromosome section) Doubling of a section C:

Inversion(chromosome break and 180 o turn) Inversion of the DE region:

During interchromosomal rearrangements, non-homologous chromosomes exchange sections - translocation occurs. Translocation a section of one of the chromosomes (pair 21) may cause Down syndrome.

Genomic mutations. The set of interacting genes contained in a haploid set of chromosomes is called a genome. Mutations associated with changes in the number of chromosomes are called genomic. A change in the number of chromosomes is caused by a violation of their distribution among daughter cells during the 1st and 2nd meiotic divisions in gametogenesis or during the first cleavages of a fertilized egg. Genomic mutations include haploidy, polyploidy, and aneuploidy (heteroploidy).

♦ Haploidy. Haploid organisms have one chromosome from each homologous pair. All recessive genes are manifested in the phenotype. The viability of organisms is reduced.

♦ Polyploidy- an increase in the diploid number of chromosomes by adding entire chromosome sets, which occurs as a result of disruption of meiotic division. For example, an organism may have (2n+n)=3n (triploid) or (2n+2n)=4n (tetraploid). Polyploid organisms have larger cells. Organisms are more resistant to adverse conditions. Polyploid plants are obtained by exposing them to chemicals (colchicine) and ionizing radiation.

♦ Aneuploidy(heteroploidy) - a change in the number of individual chromosomes - the absence (monosomy -2n-1) or the presence of additional (trisomy -2n+1, polysomy -2n+3,4,5) chromosomes. Monosomy on the X chromosome leads to the development of the syndrome

Shershevsky-Turner in women (45 chromosomes = 44 autoso-

we + X0).

Trisomydescribed by X-, Y-chromosomes and autosomes.

An extra X chromosome in men (XXY) causes the development of Klinefelter syndrome, and in women - trisomy syndrome (XXX).

Trisomythe 21st pair of autosomes is described as Down syndrome.

Syndromes in patients include disturbances in the structure and functioning of a number of organs and organ systems.

Sometimes children are born whose karyotype may contain 4, 5 X or Y chromosomes or more. For example, karyotype XXXY, XXXYY. This is polysomy.

The clinical manifestations of the syndromes in such children intensify.

If any pair of homologous chromosomes falls out of the diploid set, the organism is called nullosomic. He is not viable.

Questions for self-control

1. What is variability?

2. What is non-hereditary variability associated with?

3. What are modifications?

4. How do environmental factors influence the functions of genes and the development of the organism?

5. What causes modifications?

6. What characteristics are subject to modification variability?

7. What changes occur during hereditary variability?

8. What can be the genotypic variability?

9. What causes combinative variability?

10. What is heterosis?

11.How can heterosis be explained? 12.What are mutations?

13. What types of mutations are there?

14. What are mutations associated with?

15.What happens during gene mutations? 16.What chromosomal rearrangements do you know? 17.What are genomic mutations associated with? 18. What genomic mutations do you know?

Keywords of the topic “Variability”

aneuploidy protein

biochemical reaction

Down's disease

relationship

humidity

influence

external environment

impact

emergence

insert

breeding loss haploidy gene mutations genome

genomic mutations

genotype

genes

heterosis

heteroploidy

hybridization

eyes

peas

blood type action deletion children

addition

duplication

animals

life

replacement

radiation

changes

variability

inversion

karyotype

colchicine

crossing over

weight

meiosis

mitosis

modifications

mutagenesis

mutagens

mutations

Availability

violation

inheritance

a lack of

reaction norm

nucleotides

nullosomic

coloring

organism

absence

generation

polyploidy

receiving

subsequence

offspring

appearance

sign

cause

gap

plant

result

parents

height

light

property

breeder

seeds

crossing

plant varieties

combination

ability

structure

temperature

tetraploid

translocation

triploid

trisomy

doubling

productivity

condition

living conditions

environmental conditions

loss

plot

factor

phenotype

functions

chromosomal rearrangements

primrose flower

Part

Human

The invention relates to agriculture, namely to methods for changing the hereditary characteristics of plants. Essence: pea seeds are exposed to Co 60 gamma rays at a dose of 50 Gy, followed by exposure to laser beams in the ultraviolet region. The exposure of the latter is 5 30 minutes. As a result of processing, new mutant lines were created. 7 tables 4 ill.

The invention relates to agriculture, namely to methods for changing the hereditary characteristics of peas. There is a known method for treating peas with chemical mutagens, in which seeds of various pea varieties are soaked in solutions of chemical mutagens N-nitroso-N-ethylurea at a concentration of 0.025% for 5 hours, pH 4 or ethyl methanesulfonate 0.015% for 12 hours, pH 6, as well as ethyleneimine 0, 02% 12 hours, pH 6. The disadvantage of this method is the high toxicity of chemical mutagens, as a result of which the germination, survival and fertility of plants in the first generation decreases (Table 1). There is a known method for treating pea seeds with gamma rays, in which the seeds are irradiated with Co 60 gamma rays at a dose of 100 Gy. The disadvantage of this method is the long-term death of plants, i.e. death of seedlings in the phase of 3-4 true leaves or at later stages of the growing season (even during the flowering period) and low frequency of occurrence of economically valuable plant traits (Table 2). The closest in technical essence is the method of treating pea seeds with ionizing radiation, in which the pea seeds are treated with Co 60 gamma rays at a dose of 50 Gy (prototype). The disadvantage of this method is also the high toxicity of irradiation, which limits the use of increased doses of gamma rays and reduces the potential for mutagenesis, since a high percentage of seedling death in M1 leads to the loss of potential mutations. The disadvantage of this method is also the low fertility of plants in M ​​1, which leads to a decrease in the number of plants of the second mutant generation (M 2); as a result, the frequency of economically valuable mutations and their spectrum decreases (Table 3). The purpose of the proposed method is to increase the survival rate of plants during processing and to increase the yield of morphological, physiological and economically valuable hereditary traits of pea plants. This goal is achieved by the fact that (unlike the prototype) in the proposed method, pea seeds are exposed to laser irradiation in the ultraviolet region with pre-treatment with Co 60 gamma rays. Comparison of the claimed technical solution not only with prototypes, but also with other technical solutions in this field of agriculture made it possible to identify a technical solution containing a feature similar to the feature that distinguishes the claimed solution from the prototype: treatment of pea seeds after irradiation with gamma rays with ultraviolet laser light, which contributes to the acquisition of a greater number of new hereditary characteristics of pea plants due to greater plant survival in M ​​1. In the proposed method, laser radiation, being strictly monochromatic, is absorbed by certain components of the seed coat of the endosperm and embryo after exposure to gamma rays. After the absorption of a light quantum, the photochemical stages of the reaction begin, during which a new photoproduct is formed, which participates in further physicochemical transformations in the cell. In particular, these are conformational rearrangements of enzymes, biological membranes and other cellular structures. The accumulation and use of such energy by the cell is ensured in chloroplasts and mitochondria due to photosynthetic and oxidative formation. EXAMPLE 500 seeds of two non-shattering pea varieties of different genotypes, Truzhenik and Usach intensive, were treated with Co 60 gamma rays on the RKhM--M installation at a dose of 50 Gy, followed by exposure to UV rays of an LGI-21 pulsed laser, the gas-discharge tube of which is filled with spectrally pure nitrogen with with a small addition of argon for 5.30 minutes in duplicate. Irradiated seeds were sown in single-row plots with a feeding area of ​​10x30 cm. During the growing season, careful phenological observations were carried out at the stages of organogenesis. Since the mutations are mainly recessive, they did not appear in the heterozygous state (M 1 plants). However, single mutations in M ​​1 were observed, having a recessive and dominant nature. Therefore, seeds from each plant M 1 in the second generation (M 2) were sown in separate families. Seeds of control varieties were also sown. One family had from 20 to 30 plants. Mutations were isolated by carefully examining plants of all families during the main phases of growth and development. In the phase of full germination, mutations with chlorophyll changes were taken into account. Before flowering and during flowering, morphological mutations of early flowering and early ripening were detected. During harvesting, mutations in productivity and individual elements of productivity were taken into account, and plant survival was determined. The frequency of mutations in M2 was determined by the percentage of mutation families and plants with changes in them. Mutants M2, which showed the best results for economically valuable traits at the level of the control variety in M3, were transferred to the breeding nursery in the first year of study for the subsequent selection of constant lines. In M 2 and M 3, simultaneously with biometric indicators, biochemical studies of seeds in plants isolated according to economically valuable traits for protein were carried out. The protein content in M ​​3 was carried out using a modified method without grinding seeds on an infrared analyzer "Infrapid-61" in order to preserve the seed material of the best plants. In M 1, a stimulating effect of laser irradiation on plant survival compared to gamma rays of seeds and their increased resistance were observed (Table 4). In M 2, 965 families and 18,350 plants of the Truzhenik variety and 782 families of 17,000 plants of the Usach intensive variety were studied. In M 2, plants with altered morphological characteristics were identified (multiple fruits from 3 to 5 beans per fruit bearing, with a determinate type of stem, with a thickened stem resistant to lodging, with powerful tendrils), as well as with signs of increased productivity and a shorter growing season (by 6 -12 days). When analyzing seeds from such plants, an increased protein content was revealed, which ranged from 27.3 to 31.0% (for the standard 23.6-25.4%). For reseeding in M ​​3, 82 plants were selected for the Truzhenik variety, of which 12 were early ripening, 61 with high productivity, 8 relatively resistant to lodging, and for the Usach intensive variety 10 early ripening, 18 highly productive, 7 with multi-flowered inflorescences (multi-fruited), 7 relatively resistant to lodging. lodging 11. In the variety Truzhenik, plants were selected that combine a complex of traits: prolificacy (up to 5 beans per fruit bearing), determinate type of stem growth, drought resistance and increased early ripening; in the Usach intensive variety, plants were selected that combine a complex of traits: prolificacy, early ripening, drought resistance and deterministic type of stem growth. No such plants were found when treated with gamma rays or with the standard. Seeds from these plants were sown separately. In M 4, when analyzing plants in the field conditions of the Progress collective farm in the Lugansk region, the characteristics by which the plants were selected in M ​​2 were confirmed. Tables 5 and 6 show the results of the analysis of plants selected in M ​​2. In table Figure 7 shows the characteristics of economically valuable mutant lines obtained from seed treatment with gamma rays and UV laser light, which are donors for obtaining new pea varieties (according to M 4 data). They are capable of transmitting mutant characteristics to offspring during sexual reproduction. Thus, the advantages of the proposed method for obtaining economically valuable pea mutations (compared to the prototype) include: high repeatability of directed changes in the heredity of economically valuable traits; their stable high heredity, which makes it possible to obtain new source material to expand the gene pool of this crop and create donors for selection and genetic research; reduction of long-term plant death (survival), which increases the possibility of selecting micro- and macromutations of peas.

Think!

Questions

1. Which chromosomes are called sex chromosomes?

2. What are autosomes?

3. What is homogametic and heterogametic sex?

4. When does genetic determination of sex occur in humans and what causes this?

5. What mechanisms of sex determination do you know? Give examples.

6. Explain what sex-linked inheritance is.

7. How is color blindness inherited? What color perception will children have whose mother is colorblind and whose father has normal vision?

Explain from the perspective of genetics why there are many more colorblind people among men than among women.

Variability- one of the most important properties of living things, the ability of living organisms to exist in various forms, to acquire new characteristics and properties. There are two types of variability: non-hereditary(phenotypic, or modification) and hereditary(genotypic).

■ Non-hereditary (modification) variability. This type of variability is the process of the emergence of new characteristics under the influence of environmental factors that do not affect the genotype. Consequently, the resulting modifications of characteristics - modifications - are not inherited. Two identical (monozygotic) twins who have exactly the same genotypes, but by the will of fate grew up in different conditions, can be very different from each other. A classic example demonstrating the influence of the external environment on the development of traits is the arrowhead. This plant develops three types of leaves depending on the growing conditions - in the air, in the water column or on the surface.

Under the influence of ambient temperature, the color of the Himalayan rabbit's fur changes. The embryo, developing in the mother's womb, is exposed to elevated temperatures, which destroys the enzyme necessary for fur coloring, so rabbits are born completely white. Soon after birth, certain protruding parts of the body (nose, tips of the ears and tail) begin to darken because the temperature there is lower than elsewhere and the enzyme is not destroyed. If you pluck an area of ​​white fur and cool the skin, black fur will grow in that area.

Under similar environmental conditions in genetically similar organisms, modification variability has a group character, for example, in the summer, most people, under the influence of UV rays, deposit a protective pigment in the skin - melanin, people sunbathe.

In the same species of organisms, under the influence of environmental conditions, the variability of various characteristics can be completely different. For example, in cattle, milk yield, weight, and fertility very much depend on feeding and housing conditions, and, for example, the fat content of milk changes very little under the influence of external conditions. Manifestations of modification variability for each trait are limited by their reaction norm. Norm of reaction- these are the limits within which a change in a trait is possible in a given genotype. In contrast to modification variability itself, the reaction norm is inherited, and its boundaries are different for different traits and in individual individuals. The narrowest reaction norm is characteristic of traits that provide vital qualities of the body.

Due to the fact that most modifications have adaptive significance, they contribute to adaptation - the adaptation of the organism, within the limits of the reaction norm, to existence in changing conditions.

■ Hereditary (genotypic) variability. This type of variability is associated with changes in the genotype, and the traits acquired as a result of this are inherited by subsequent generations. There are two forms of genotypic variability: combinative and mutational.

Combinative variability consists in the appearance of new characteristics as a result of the formation of other combinations of parents’ genes in the genotypes of offspring. This type of variability is based on the independent divergence of homologous chromosomes in the first meiotic division, the random encounter of gametes in the same parental pair during fertilization, and the random selection of parental pairs. The exchange of sections of homologous chromosomes that occurs in the first prophase of meiosis also leads to recombination of genetic material and increases variability. Thus, in the process of combinative variability, the structure of genes and chromosomes does not change, but new combinations of alleles lead to the formation of new genotypes and, as a consequence, to the appearance of descendants with new phenotypes.

Mutational variability is expressed in the emergence of new qualities of the organism as a result of the formation of mutations. The term “mutation” was first introduced in 1901 by the Dutch botanist Hugo de Vries. According to modern concepts, mutations are sudden natural or artificially caused inherited changes in genetic material, leading to changes in certain phenotypic characteristics and properties of the organism. Mutations are non-directional, i.e. random, in nature and are the most important source of hereditary changes, without which the evolution of organisms is impossible. At the end of the 18th century. In America, a sheep with shortened limbs was born, giving rise to the new Ancona breed. In Sweden at the beginning of the 20th century. A mink with platinum-colored fur was born on a fur farm. The huge variety of traits in dogs and cats is the result of mutational variability. Mutations arise spasmodically, as new qualitative changes: awnless wheat was formed from awned wheat, short wings and strip-shaped eyes appeared in Drosophila, and white, brown, and black colors appeared in rabbits from the natural agouti color as a result of mutations.

According to the place of occurrence, somatic and generative mutations are distinguished. Somatic mutations arise in the cells of the body and are not transmitted through sexual reproduction to subsequent generations. Examples of such mutations are age spots and skin warts. Generative mutations appear in germ cells and are inherited.

Based on the level of change in genetic material, gene, chromosomal and genomic mutations are distinguished. Gene mutations cause changes in individual genes, disrupting the order of nucleotides in the DNA chain, which leads to the synthesis of an altered protein.

Chromosomal mutations affect a significant portion of the chromosome, leading to disruption of the functioning of many genes at once. A separate fragment of a chromosome can be doubled or lost, which causes serious disruptions in the functioning of the body, including the death of the embryo in the early stages of development.

Genomic mutations lead to a change in the number of chromosomes as a result of violations of chromosome segregation during meiotic divisions. The absence of a chromosome or the presence of an extra one leads to adverse consequences. The most well-known example of a genomic mutation is Down syndrome, a developmental disorder that occurs when an extra 21st chromosome appears. Such people have a total number of chromosomes of 47.

In protozoa and plants, an increase in the number of chromosomes that is a multiple of the haploid number is often observed. This change in chromosome set is called polyploidy. The emergence of polyploids is associated, in particular, with the nondisjunction of homologous chromosomes in meiosis, as a result of which in diploid organisms diploid rather than haploid gametes can be formed.

Mutagenic factors. The ability to mutate is one of the properties of genes, so mutations can occur in all organisms. Some mutations are incompatible with life, and the embryo that receives them dies in the womb, while others cause persistent changes in characteristics that are significant to varying degrees for the life of the individual. Under normal conditions, the frequency of mutation of an individual gene is extremely low (10 -5), but there are environmental factors that significantly increase this value, causing irreversible damage to the structure of genes and chromosomes. Factors whose impact on living organisms leads to an increase in the number of mutations are called mutagenic factors or mutagens.

All mutagenic factors can be divided into three groups.

Physical mutagens are all types of ionizing radiation (y-rays, x-rays), ultraviolet radiation, high and low temperatures.

Chemical mutagens- these are analogues of nucleic acids, peroxides, salts of heavy metals (lead, mercury), nitrous acid and some other substances. Many of these compounds cause problems with DNA replication. Substances used in agriculture to control pests and weeds (pesticides and herbicides), industrial waste, certain food colorings and preservatives, some medications, and components of tobacco smoke have a mutagenic effect.

In Russia and other countries of the world, special laboratories and institutes have been created that test all new synthesized chemical compounds for mutagenicity.

MINISTRY OF AGRICULTURE OF THE RF

FEDERAL STATE BUDGET EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

"AZOV-BLACK SEA STATE AGRICULTURAL ENGINEERING ACADEMY"

Department: "Breeding and genetics of agricultural crops"

COURSE WORK

ON THE GENETICS OF POPULATIONS AND QUANTITATIVE TRAITS

Topic: "Analysis of the inheritance of quantitative traits in pea hybrids"

Completed by: student KSG-31

Moiseenko I. V.

Checked: k.s. - X. Sc., Associate Professor

Kostyleva L. M.

Zernograd 2012

Introduction

1. Literature review

1.1 Botanical description

1.2 Pea genetics

3. Research results

3.1 Number of beans

3.2 Weight of grains per plant

4. Conclusions

Bibliography

Applications

Introduction

Peas (genus Pisum L.) belong to the legume family Fabaceae Lindl. (Leguminosae Juss.), fetlock-Vicieac Broil. P. sativum L. sensu amplissimo Govorov-peas are the main grain legume crop in our country, which ranks second in the world in terms of planted area (after China). The wide distribution of peas is due to the high protein content in the grain (on average 20-27%), the balance of its amino acid composition, good taste and digestibility, and fairly high potential yield in almost all cultivation zones.

Peas are currently fed to animals in the form of grain, green mass, and hay. They are also used to prepare grass meal, haylage, silage, and protein-vitamin concentrates. Peas contain all the essential amino acids. Thus, on average, the lysine yield per 1 ha is: for peas - 21.7; for barley - 6.77; for corn - 8.16 kg. Based on this, 1 ton of peas can balance the protein and amino acid composition of 5 tons of grain from other grain crops, thereby eliminating the overconsumption of feed when fattening pigs by up to 45-50%. The green mass of peas, harvested in the flowering phase, is close in nutritional value to alfalfa and sainfoin, and pea straw is not inferior to hay of average quality. Peas also occupy a significant place in vegetable farming. Unripe beans and green peas are consumed fresh or canned. In addition, peas, due to their nitrogen-fixing ability, are one of the best precursors for almost all crops. After it, up to 100 kg/ha of bound, easily accessible nitrogen remains in the soil, which is very important in the biologization of agriculture. This is an excellent fallow crop and can be widely used as a green fertilizer.

Peas are the main legume crop in Russia. It is cultivated on an area of ​​1-1.2 million hectares, accounting for 82% of all grain leguminous crops. The main crops are concentrated in the Central Black Earth zone, in the North Caucasus. In the Rostov region, its crops amount to 10-15 thousand hectares, approximately 10-15 times less than in pre-perestroika times. This is primarily due to the reduction in livestock farming in the region. Currently, in the Southern Federal District for 2011, 12 varieties of peas are approved for use. The most common of them are baleen forms: Aksai baleen 5; Aksai mustachioed 7; Aksai mustachioed 10; Priazovsky (DZNIISH), Flagman (Samara Research Institute of Agriculture), Legion (Krasnodar Research Institute of Agriculture) with a potential yield of up to 4.0-4.5 t/ha.

The common pea is an important crop and a useful model for genetic research. Peas are grown as food and feed crops. The main problems of growing peas as an industrial crop are the relatively low and variable yield, as well as the difficulties encountered during harvesting. Significant morphological polymorphism in peas provided a sufficient number of markers for the first genetic studies and laid the foundation for the construction of the first genetic maps.

Maps of pea chromosomes containing molecular markers have now been published. Thanks to the use of common markers, it was possible to create a “consensus” map of chromosomes that combined morphological and molecular loci. There is a small number of QTL mapping studies using seed mass, height and number of nodes, and disease resistance. However, a detailed map of pea chromosomes has not yet been created, and additional search for new morphological and molecular markers and their localization is required.

Purpose of the course work:

Study of the inheritance of quantitative traits in pea hybrids F 5Sarmat

Formation of skills in analyzing the inheritance of quantitative traits of peas in segregating hybrid populations, which is necessary in breeding work.

Conduct a genetic analysis of quantitative traits of F5 pea hybrids .

Present the results of the analysis in the form of tables, graphs and text, which describe the obtained patterns.

Establish the nature of splitting, the strength and number of genes responsible for specific traits.

inheritance of quantitative trait pea

1. Literature review

1.1 Botanical description

Pea plants have a vaguely tetrahedral hollow stem, simple or fasciated in the so-called standard forms. Based on the height of the stem, there are dwarf (less than 40 cm), semi-dwarf (41-80 cm), medium-sized (81-150 cm) and tall (151-300 cm) forms. Branching of the stem is of two types: at the base and axillary along the stem.

The leaves are usually pair-pinnate with 1-3 pairs of leaflets ending in tendrils, but there are also odd-pinnate leaves with 7-15 leaflets without tendrils, many times imparipinnate, and there are also forms with only tendrils (without leaflets). The stipules are semi-heart-shaped, usually larger than the leaflets. Stems, leaves, stipules and beans are usually covered with a waxy coating.

The inflorescence is axillary and in most forms consists of 1-2 flowers. But there are samples that, under favorable conditions, produce up to 11 flowers on a peduncle. In standard forms, peduncles are concentrated in the upper part of the stem, forming a false umbrella.

Flowers of different sizes, moth-like. The color of the corolla is white, purple, dirty purple, pink, crimson (reddish-red). At the same time, the wings of painted flowers often have a more intense shade than the sail. The stamens are bifraternal (9 fused and 1 free), one pistil is curved, with hairs on the stigma.

The beans are cylindrical, of various shapes: straight, curved, saber-shaped, sickle-shaped, bead-shaped, xiphoid. The top of the bean is blunt or sharp, sometimes retracted.

The length of the bean is 3-15 cm. Each bean contains 3-8, sometimes up to 10 seeds of various sizes (the weight of 1000 seeds is from 40 to 450 g). The shape of the seeds can be round, oval, rounded-angular, compressed; surface - with depressions, smooth, wrinkled. The color of the seeds is yellow, yellow-pink, green, bluish-green, brown, plain or with purple mottled, hairy or marbled, dark purple, almost black. The scar is light, brown or black.

1.2 Pea genetics

The study of pea genetics began with the famous experiments of Mendel, and since then work in this direction has been intensively carried out in many countries of the world. Peas are a very convenient genetic object, since it is a strict self-pollinator with clearly distinguishable morphological characters, and also has a small number of chromosomes (2n=14), which correspond to 7 linkage groups.

To date, more than 200 genes with 400 alleles have been studied in peas. More than 160 genes are mapped onto the chromosome. Much credit for the development of private pea genetics belongs to the Swedish scientist H. Lamprecht.

Stem. Stem fasciation is caused by recessive alleles fa and fas. Plants with genotypes FaFas, Fafas and faFas have a normal stem.

The length of the stem depends on the action of many genes. Some of them control the length of internodes, others control the number of nodes on the stem. In practical breeding work, it is advisable to consider stem length as a polygenic trait and use the appropriate formulas of quantitative genetics.

The time at which the variety begins to bloom depends on which node produces the first flower. Plants with the dominant Lf allele are late-ripening, their first flower is formed on the 12-14th node, forms with the recessive lf allele form lower flowers on the 9-11th node. Stem branching is determined by the Fr and Fru genes. On plants with the FrFru genotype, from one to four branches are formed, and on plants with the frfru genotype, from 5 to 10 branches. Frfru and frFru genes have intermediate type plants. The pleiotropic effect of the fru gene has been established - plants with this gene are shorter, faster ripening and less productive.

Leaf and stipule. Leaf color is determined by the action of several genes. The number of leaflets in a pinnate leaf is determined by the Up gene. The dominant allele causes 2-3 pairs of leaves, the recessive allele causes one pair of leaves. An odd pinnate leaf of the acacia type is formed when Tl transitions into a recessive form. The recessive allele af causes the formation of a leafless ("moustached") leaf.

Inflorescence. Of particular interest when breeding peas are multi-flowered forms. The number of flowers on a peduncle is controlled by two genes - Fn and Fna. In the dominant state, both genes cause the appearance of inflorescences with only one flower. Forms with genotypes Fnfna and fnFna have paired flowers. Multi-flowered forms (fnfna) produce 3 or more flowers. The number of beans on a fruiting plant also depends on the Pn gene, but in a recessive state it affects not the formation, but the abscission of already formed flowers. The length of the peduncle is determined by the factors Pr and Pre. Long peduncles dominate.

Flower. The color of the corolla depends primarily on gene A, which in the dominant state determines the purple color of the petals. The recessive allele a causes a white corolla and a lack of anthocyanin in other parts of the plant. Other genes also influence petal color. Flower fertility is determined by the genes Ms1, Ms2 and Ster. The recessive allele ms1 disrupts meiosis in early prophase and in late phases. The ms2 gene causes female sterility. Large flowers are formed under the influence of the Pafl gene, while the recessive gene (pafl) causes small flowers.

Fetus. The shape of the bean depends on the genes Con, Co, N, Cp. In this case, the genotypes ConsoCpN, ConsoCpN, conCoCpn, conCopn, concoCpn, concopn determine straight beans; conCoSpN, conCospN, concospN-slightly curved; ConsoCrn, Consocpn and Consocpn-curved. Curved beans have more ovules than straight ones. When the Bt gene is combined with N, a blunt top of the bean is formed; when btn, btN and Btn are combined, a pointed one is formed.

The parchment layer in the bean valves develops in the presence of dominant genes P and V. In such plants, the beans become severely cracked when ripe. The pV genotype causes the formation of a parchment layer in the form of thin strands, Pv - in the form of small spots. Molds with pv lack the parchment layer (sugar beans). The total thickness of the valves depends on the N gene. With a recessive allele, this figure increases by 50-80%.

The size of the bean depends on several genes: with the recessive alleles laf, te and ten, the width decreases, in the presence of the lt allele it increases. The Miv gene affects the arrangement of ovules in the pod: with the recessive allele they are located more closely.

2. Materials and research methods

The material for the study was hybrid populations of pea F 5, obtained from crossing Aksai Mustached 10 × Sarmat. Sowing of hybrid seeds was carried out manually on experimental plots of the UOFH AChGAA.

As a result, plant heights were measured, the number of internodes, the length of each internode, the number of beans, the number of grains in a bean, and the weight of grains per plant were calculated. Measurements were made using a measuring ruler, and grain mass was calculated using laboratory scales.

During the primary analysis, data were entered into MS Excel.

Further data analysis was carried out using the Polygen A program according to the method of Merezhko A. F., 1984.

3. Research results

3.1 Number of beans

The Sarmat variety was taken as the parent with the minimum value of the trait; the average value is 4.24 beans. The sample size is 21 plants. The average value of the trait for the parent with the maximum value is 5.2 beans, the sample size is 20 plants. The sample size of the hybrid is 550 plants.

The parent forms differ by 1 bean. The average value of the trait in a hybrid goes beyond the values ​​of the parent forms, but is closer to the smaller parent. This means that the dominance of the lower value of the attribute is observed. The dominance indicator (hp) is - 1.442.

Rice. 1. Frequency distribution curve of the number of beans in parents and hybrids.

The graph has right-hand asymmetry and three peaks. (Fig. 1.)

Cleavage 3:1, i.e. according to the monohybrid scheme. The gene strength is 1 bean.

3.2 Weight of grains per plant

The variety Sarmat was taken as the parent with the minimum value of the trait; the average value is 4.05 g. The average value of the trait for the parent with the maximum value is 4.94 g.

Rice. 2. Frequency distribution curve of grain mass per plant for parents and hybrids.

The parental forms and the hybrid had the same values, and the tops of the distribution curves were located in the same class. (Fig.2.)

This indicates the absence of genetic differences in this trait between the parental individuals and the hybrid. The dominance indicator (hp) is - 1.975, i.e. dominance of the lower value of the trait and hybrid depression are observed.

3.3 Number of grains per plant

The variety Aksaisky Usatiy 10 was taken as the parent with the minimum value of the trait; the average value is 17.7 grains. The average value of the trait for the parent with the maximum value is 18.19 grains.

Parent forms differ in ½ grains The average value of the trait in a hybrid goes beyond the values ​​of the parent forms, but is closer to the smaller parent. This means that the dominance of the lower value of the attribute is observed. The dominance indicator (hp) is - 11.3.

Fig.3. Frequency distribution curve of the number of grains per plant for the parents and the hybrid.

The graph has a right-hand asymmetry. (Fig. 3.) Segregation occurs according to a monohybrid scheme.

4. Conclusions

1. During the course work, a genetic analysis of quantitative traits of pea hybrids F was carried out 5from crossing Aksai mustachioed 10 × Sarmat.

As a result of the genetic analysis of quantitative traits, the following results were obtained:

A) According to the trait number of beans, the parent forms differ by 1 bean; dominance of the lower value of the trait is observed. The dominance indicator (hp) is - 1.442. Cleavage 3:1, i.e. according to the monohybrid scheme. The gene strength is 1 bean.

B) According to the trait weight of grains per plant, the parental forms and the hybrid had the same values, and the tops of the distribution curves were located in the same class; there were no genetic differences for this trait between the parental individuals and the hybrid. The dominance indicator (hp) is - 1.975.

C) Parent forms differ in ½ grains The average value of the trait in a hybrid goes beyond the values ​​of the parent forms, but is closer to the smaller parent. This means that the dominance of the lower value of the attribute is observed. The dominance indicator (hp) is - 11.3. The graph has a right-hand asymmetry. (Fig. 3.) Segregation occurs according to a monohybrid scheme.

As a result of the course work, all the goals and objectives were achieved.

Bibliography

1. Guzhov Yu.L. et al., Selection and seed production of cultivated plants, // M.: Agropromizdat, 2004, 463 p.

Guzhov Yu.L., Patterns of variation in quantitative traits in peas due to modifications and genotypic differences, Genetics, 2000, v. 18, pp. 283-291.

3. Internet resources:<#"center">Applications

Annex 1

Number of beans

Statistical parameters of parental forms and hybrid F2 Parameters Pmin Pmax F2 Sample size - n2120550 Average sample value - X4.245, 204.03 Standard deviation - Sx0.9951.7651.691 Error of sample mean - Sosh. 0.2170.3950.072 Coefficient of variation - Cv%23.4833.9542.00Maximum option - Max6.09.09.0Minimum option - Min3.03.01.0Lower confidence interval - X-3Sx1.3-0.1-1 ,0Upper confidence interval - X+3Sx7,210,59,1Dominance indicator in F2-1,442

Variant frequencies (in % and numbers) in classes with average values: 0.21.73.14.66.07.58.9Sarmat 0.00.023.861.914.30.00.0F20.018.220.944.08.76.51.6Ax. Us.100,00,015,045,020,015,05,0

Appendix 2

Weight of grains per plant

Statistical parameters of the parental forms and the hybrid F2 Parameters Pmin Pmax F2 Number of sample - n2120555 Average sample value - X4,054,923,62 Standard deviation - Sx0,8282,2662,377 Error of sample mean - Sosh. 0.1810.5070.101 Coefficient of variation - Cv%20.4746.0365.68 Maximum option - Max5.311.110.5 Minimum option - Min2.42.10.0 Lower confidence interval - X-3Sx1.6-1.9-3.5 Upper confidence interval - X+3Sx6,511,710,8 Dominance indicator in F2-1,975

Variant frequencies (in % and numbers) in classes with average values: 0.72,44,05,77,39,010,612,313,9Sarmat0,019,061,919,00,00,00,00,00,0F29,921,827,017,77,42,90, 90,20,4Ax. Mustache 100,020,045,020,05,05,05,00,00,0

Appendix 3

Number of grains per plant

Statistical parameters of parental forms and hybrid F2 Parameters Pmin Pmax F2 Number of sample - n2021550 Average sample value - X17.7018, 1915.17 Standard deviation - Sx8.5233.8688.449 Error of sample mean - Sosh. 1.9060.8440.360Coefficient of variation - Cv%48.1521.2655.69Maximum option - Max41.025.067.0Minimum option - Min7.012.00.0Lower confidence interval - X-3Sx-7.96.6-10.2Upper confidence interval - X+3Sx43.329.840.5 Dominance indicator in F2-11.305

Variant frequencies (in % and numbers) in classes with average values: 2.99,315,622,028,434,841,247,553.9Ax. Usat 100,035,035,015,010,00,05,00,00,0F214,227,528,020,06,22,21,10,20,2Sarmat0,04,852,442,90,00,00,00,00,0

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The great Czech scientist Gregor Mendel was the first researcher in the history of biology who, using the simple and objective method of hybridization he developed, managed to discover the basic patterns of inheritance of characters.

1) Explain why G. Mendel is often called the founder of genetics.

Answer: Mendel formulated the basic laws of genetics and explained the transmission of hereditary characteristics from parents to offspring.

2) What organisms did G. Mendel conduct his experiments on? What properties do they have that are convenient for genetic research?

Answer: Peas. It produces many seeds, is a self-pollinating plant, and has a closed flower.

3) Fill in the blanks in the sentences.

Answer: Plants that have homogeneous genes , obtained with selection , self-pollination, is called clean lines.

4) Consider the diagram “Flowers of the night beauty plant.” Name dominant and recessive traits. What is represented by the letters A and a?

What genotype is characteristic of the first generation hybrid (F 1)? What is this type of inheritance of the color of the corolla of night beauty flowers called? What law expresses the letter designation of the genotype of a first generation hybrid? Write down what offspring might appear in the second generation of plants with pink flowers.

5) Study the data in the table “Results of Mendel’s experiments on crossing pea varieties,” which presents the results of some of G. Mendel’s experiments. Find the dominant traits. Which column of the table illustrates Mendel's first law - the rule of dominance. Which column summarizes the results of Mendel's second law?

Answer: Dominant characteristics are red, tall, swollen. Signs - 1 law; second hybrid generation - 2nd law.

6) Formulate Mendel's first and second laws. What is incomplete dominance? Indicate the phenotypes and genotypes of the parental forms. Illustrate your answer with examples.